#include <cstdio>
#include <iostream>

using namespace std;

const int N = 10005;

int n, cnt[10], ans = 0;

char s[30];

void dfs(int u, int a, int b, int c, int d, int e) {
    if (u == 10) {
        ans = max(ans, min(min(min(min(a, b), c), d), e));
        return;
    }
    dfs(u + 1, a + cnt[u], b, c, d, e);
    dfs(u + 1, a, b + cnt[u], c, d, e);
    dfs(u + 1, a, b, c + cnt[u], d, e);
    dfs(u + 1, a , b, c, d + cnt[u], e);
    dfs(u + 1, a, b, c, d, e + cnt[u]);
}

int main() {
    int T; scanf("%d", &T);
    while (T--) {
        ans = 0;
        scanf("%d", &n);
        for (int i = 0; i < 10; i++) cnt[i] = 0;
        for (int i = 1; i <= n; i++)
            scanf("%s", s), cnt[s[4] - '0']++;
        dfs(0, 0, 0, 0, 0, 0);
        printf("%d\n", n - ans);
    }
    return 0;
}